Circuit interrupter



W. M. LEEDS CIRGUIT INTERRUPTER July 2, 1946.

5 SheetS- -Sheet 1 Filed Feb. 20. 1945 ENVENTOR W272 f/770 D M. L 6662 5.

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July 2, 1946. w. M. LEEDS CIRCUIT INTERRUPTER Filed Feb 20, 1943 5 Sheets-Sheet 2 INVENTOR WZiYZ/ZZ'OP M Leeds. 6 BY 71/ ATTORNEY y w. M. LEEDS 2,403,103

CIRCUIT INTERRUPTER Filed Feb. 20,194s 5 SheetsSheet 3 :I QI

' INVENT'OR Winthrop M Leeds.

y 1946- w. M. LEEDS 03, 03 I CIRCUIT INTERRUPTER' I Filed Feb. 20, 1943. 5 Sheets-Sheet 4 153 INVENTOR MHz/2250 MLeaas.

W. M. LEEDS CIRCUIT INTERRUPTER July 2, 1946.

s Sheets-Sheet Filed Feb. 20, 1943 Material 14 5 Mhf/Yrqa M Leeds.

BY i ATTORNE Magnetzz' WITNESSES:

Patented July 2, 1946 CIRCUIT INTERRUPTER Winthrop M. Leeds, Wilkinsburg, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application February 20, 1943, Serial No. 476,510

This invention relates the circuit interrupters in general, and, more particularly, to are extinguishing structures therefor.

First, during the greater portion of time are current is flowing, particularly in the region of the peak of the current wave, the arc should be disturbed as little as possible by cross blasts, restricting walls, or strong magnetic action, so as to keep the arc voltage and the consequent gas generation as low as possible. Second, vents, passages and liquid flow should be arranged to drive the products of decomposition of the are out of the arc chamber as fast as they are formed so as to maintain high dielectric in the arc chamber and keep the internal pressure reasonably low. Third, just prior to current zero when the arc current is relatively low, strong deionizing action should be brought into play, as for instance, subjecting the arc to turbulent crossblasts of liquid and gas, confining the arc within a restricted passage or rapidly moving or lengthening the arc. These methods of treatment to produce rapid deionization, either singly or in combination, though preferably the latter, insure complete interruption of the circuit at current zero.

The main object of my invention is to provide an improved arc rupturing device which functions in accordance with the aforementioned principles.

Another object of my invention is to provide an improved circuit interrupter in which the are established is moved laterally, and to drive fluid at the are after it has moved laterally to eifect its extinction.

Another object is to provide an improved circuit interrupter in which is produced both a first flow of fluid and a second flow of fluid. I use the first flow of fiuid to assist moving the established arc laterally, and arrange the sec- 26 Claims. (Cl. 200--150) 0nd flow of fluid to contact the are after it has moved laterally to effect its extinction.

Another object is to provide an improved circuit interrupter in which is produced a flow of fluid. I establish an are not in the flow of fluid and move it laterally into the flow to effect its extinction.

A more specific object of my invention is to provide an improved circuit interrupter in which an arc is established, and to provide means for moving the arc laterally during relatively low instantaneous values of arcing current. I also provide means for driving fluid into the are after it has been moved laterally to effect its extinction.

Further objects and advantages will readily 2 become apparent upon a reading of the following specification taken in conjunction with the drawings, in which:

Figure 1 is a View taken in vertical section on line II of Fig. 3 of a circuit interrupter embodying my invention and shown in the open circuit position;

Fig. 2 is a View taken substantially on the line 11-11 of Fig. 1;

Fig. 3 is a view in cross section taken on the line III-III of Fig. 1;

Fig. 4 is a vertical sectional View taken on the line IVIV of Fig. 3;

Figs. 5 through 26 show plate details;

Fig. 27 is a plan view of a support plate;

Fig. 28 is a sectional view taken on the line XXVIIIXXVIII of Fig. 27;

Fig. 29 is an elevational view in vertical section taken through a modified type circuit interrupter embodying my invention, the interrupter being shown in the open circuit position;

Fig. 30 is a view taken on the line XXX-QQCX of Fig. 29;

Fig. 31 is a view in section taken on the line XXXI-XXXI of Fig. 29;

Fig. 32 is a View in section taken on the line XXXIIXXX II of Fig. 31; and

Fig. 33 is an elevational view of 'a' circuit interrupter of the type shown in Fig. 29 supported in a suitable casing, the parts being shown in the open circuit position.

Referring to. the drawings and, more particularly, to Fig. 1 and Fig. 33, the reference numeral I generally designates an arcextinguishing assemblage comprising a plurality, in this instance two, are extinguishing units 2 disposed within a weather-proof casing 3 (see Fig. 33). An annular terminal and support plate 4 is supported on the casing 3 and supports a housing 5, only a portion of which is shown. A line terminal 8 is connected to the support plate 4.

Insulating tie rods 1 support the arc extinguishing units within the casing 3, and insulating spacing sleeves8 maintain the arc extinguishing units in spaced relation with respect to each other and also with respect to the terminal and support plate 4. Nuts 9 are utilized to secure the tie rods 1 to the support plate 4 and also to maintain the insulating plates forming the arc extinguishing units in a compressedrelation.

Referring to Fig. 1, the top insulating plate ID of each arc extinguishing unit 2 is shown more clearly in Figs. 5 and 6. It will be observed that circular apertures it are provided. in the plate I0 to accommodate the tie rods 1, A circular vent aperture I2 is provided, the purpose of which will appear more clearly hereinafter. A rectangular vent aperture I3 is provided, and circular piston guide apertures l4 are provided, the purpose for which will also appear more clearly hereinalter.

An oval-shaped aperture I5 is formed in the plate HI, and a stationary contact aperture i6 is provided in the plate I0. Two tapped apertures I! are provided in the plate Ill adjacent to the stationary contact aperture i6. A coil connector aperture 18 is provided in the plate Hi.

Immediately below the insulating top plate H) is an insulating magnet plate l9 more clearly shown in Figs. 7 and 8. The insulating rnagnet plate H! has circular apertures II for the tie rods 1, a circular vent aperture l2, circular piston guide apertures l4, a stationary contact aperture l6, and a cutout portion 2|) which accommodates the insertion of the bight portion of a U-shaped magnet 2| composed or magnetic material, in this instance iron, as more clearly shown in Fig.4.

Below the magnet plate 19 is an insulating coil plate, generally designated by the reference numeral 22, the configuration of which is more clearly shown in Figs. 9 and 10. The coil plate 22 has apertures similar to those already described. The coil plate 22 comprises three insulating parts, two of which are indicated by the reference numeral 23 and the other by the reference numeral 24. which are more clearly. shown in Figs. 9 and 10. The space 25 between the insulating parts 23, 24 is used to accommodate the insertion of coils 26, 21 (see Fig. 4) A conmotor 28 which electrically connects the coils 26, 21 is disposed in a slot 29 provided in the coil plate 22.

A coil connector stud 30 passes through the coil connector apertures |8 provided in plate I0 and partly in coil plate 22, also passing through an aperture 3| provided in the bight portion of the U-shaped magnet 2| as more clearly shown in Fig. 1. A connector 32 electrically connects the coil connector stud 30 with coil 21, the connector 32 being disposed in a slot 33 provided in the coil plate 22, as shown in Fig. 9.

A connector 34 disposed in a slot 35 provided in the coil plate 22 is connected at one end to the coil 26 and at its other end to an arcing horn screw 36, as more clearly shown in. Fig. 1. Immediately below the coil plate 22 is an insulating plate 31, more clearly shown in Figs. 11 and 12. Th plate 31 has apertures similar to those previously described and which are designated. by the same reference numerals. In addition, the plate 31' has a beveled aperture 38 for the arcin horn screwv 36. Another beveled aperture 39 is provided in the plate 31 to accommodate the other arcing horn screw 40, as shown in Fig. 1. The insulating plate 31 has two enlarged piston apertures 4| which are larger in diameter than the circular piston guide apertures 4 provided in plates l0, I9, and 22, the purpose for which will appear more clearly hereinafter.

Below the insulating plate 31 is an insulating plate 42, the configuration of which is more clearly shown in Figs. 13 and 14. The plate 42 has disposed therein an elongated slot 43 which is provided to accommodate the insertion of an upper arcing horn 44 as more clearly shown in Fig. 1. The arcing horn 44 has a grating portion 44a (see Fig. 2), the purpose for which will also appear more clearly hereinafter. The insulating plate 42 has disposed therein a plurality, in this instance four, pockets 45. A barrier portion 46 is provided between the elong ted slot 43 and the circular vent aperture 12, as shown in Fig. 13. Immediately below the insulating plate 42 is an insulating inlet plate, the configuration of which is more clearly shown in Figs. 15 and 16. The insulating inlet plate 3'1" has a passage generally designated by the reference numeral 48 of irregular outline. The passage 48 has a relatively wide portion 43 and a relatively restricted portion 53 which leads into a less restricted section at 5|, the latter communieating to the circular venting aperture l2, as more clearly shown in Fig. 15. A plurality, in this instance two, inlet passages 52 are provided in the insulating plate 41 which lead from the enlarged piston apertures 4| to the less restricted section 5|, as more clearly shown in Fig. 15.

Below the insulating inlet plate is? is an insulating pocket plate 53, the configuration of which is more clearly shown in Figs. 17 and 13. The passage 48 in the insulating pocket plate 53 has an irregular outline and has a widened portion 5:1 which leads into the pockets 45.

Then follows an insulating inlet plate 6], an insulating pocket plate 53, an insulating inlet plate 41 and an insulating pocket plate 53. Below the last insulating pocket plate 53 is an insulating arc horn plate 55, the configuration of which is more clearly shown in Figs. 19 and 20. The insulating arc horn plate has a slot 555 formed therein to accommodate the insertion of the lower arcing. horn 57. A beveled aperture 53 accommodates a lower arcing horn screw till, as more clearly shown in Fig. 1 A beveled aperture 59 provided in the insulating arc horn plate 55 accommodates, a lower arc horn screw 8|, as shown in Fig. 1.

Below the insulating arc horn plate 55 is an insulating coil plate, generally designated by the reference. numeral 82, and shown more clearly in Figs. 21 and 22. The insulating coil plate 62 comprises two insulating parts 63 and a surrounding insulating part as more clearly shown in Fig. 21. The space 25 between the parts 63 and the [part 64 is used to accommodate the insertion of coils (i5, 66, more clearly shown in Fig. 1.

A connector El electrically connects the coils 65, 56 in series and is disposed in a slot 68 provided in the insulating coil plate 62. A connector 69; (see Fig. l) secured, as by welding, to thelower arc horn screw 6| lies in a slot iii disposed in the insulating coil plate 62 and electrically connects the coil 65 with the lower arc horn iii. A connector l2 lying in a slot 1'3 provided in the insulating ecoil plate 52 electrically connects coil 66 with stud 14, as more clearly shown in Fig. 1.

The insulating coil plate 82 has disposed therein a circular aperture 75, the purpose for which will appear more clearly hereinafter. Below the insulating coil plate 62- is an insulating magnet plate ll, the configuration oi which isrnore clearly shown in Figs. 23 and 24. An aperture '18 is provided in the magnet plate TI to accommodate the stud 14. A cutout portion 29 is also provided in the insulating magnet plate TI to accommodate the insertion of a U-shaped magnet 2| composed of magnetic material, in this instance iron, as shown more clearly in Fig. 4.

The bottom insulating plate 19 of the are extinguishing unit 2 has a configuration more clearly shown in Figs. 25 and 26 The insulating plate 15. has apertures similar to those previously described and are designated by the same reference numerals.

When the insulating plates are all aligned on the insulating tie rods I and compressed by the nuts 9, the several apertures align to form elongated passages. More particularly, the enlarged piston apertures 4I align to form piston cham bers, generally designated by the reference numeral 80, and as more clearly shown in Fig. 4.

Referring to Figs. 1 and 4, it will be observed that I have provided two insulating second pistons 8i collectively constituting a. second fluid moving means which are operative into the piston chambers 80 to compress the fluid, in this instance oil, disposed in the piston chambers 80. The insulating pistons 8| are supported at their upper ends to a triangular-shaped insulating support plate 82, more clearly shown in Figs. 27 and 28. The support plate 82 has piston apertures 93 formed therein which serve to support the insulating pistons BI, nuts 84 being utilized to secure the upper portion of the insulating pistons, which are preferably threaded, to the insulating support plate 82. Also secured to the insulating support plate 82 is an insulating operating rod 85, more clearly shown in Fig. 1. The insulating support plate 82 has an operating rod aperture 89 formed therein in which the insulating operating rod 85 is secured by the nuts 81, as more clearly shown in Fig. 1.

The insulating support plate 82 has notches 88 formed therein to accommodate the insulating tie rods '1 and the sleeves 8 surrounding the tie rods 1.

Also secured to the insulating support plate 8.2 is an insulating piston member 89 more clearly shown in Fig. 1. The support plate 82 has a piston aperture 90 formed therein through which is inserted the upper end of the insulating piston member 99. Nuts 9I may secure the piston member 89 to the insulating support plate 82, as shown in Fig. 1.

The first fluid moving means or first insulating piston member 89 supports a plurality of ovalshaped insulating washers 92, 93 as more clearly shown in Fig. 1. The oval-shaped washers 92 have an external dimension that is greater than the external dimension of the oval-shaped insulating washers 93. Consequently the surface of the insulating piston member 89 is corrugated as shown in Fig. 1.

The first piston member 89 moves through the oval-shaped apertures I5 provided in plates I0, I9, 22, 3?, 42, 41, 53, and 55.

A movable contact 94. having a configuration more clearly shown in Figs. 1 and 3, is secured to the insulating piston member 89. Below the movable contact 94 is a metallic coupling member 95 making a press fit at 96 with the insulating piston member 89. Nuts 97 rigidly secure the metallic coupling member 95 to the insulating support plate 82 of the lower arc extinguishing unit 2 of Fig. 1. Threadedly secured to the metallic coupling member 95 is a spanner nut 98 which clamps a flexible conductor I06 to the piston member 89 of the lower arc extinguishing unit 2.

Extending transversely across the top of the upper arc extinguishing unit 2, as more clearly shown in Fig. 2, is a contact carrying member 99 having two spaced bolts I00 passing therethrough, which spaced bolts I00 are supported in the two tapped apertures I! provided in the top insulating plate I0. Compression springs IIJI surrounding the spaced bolts I00 and disposed between the heads of the two bolts I00 and the contact carrying member 99 serve to bias the contact carrying member downwardly as viewed in Fig. 1. Astationary contact I02 is provided. Preferably the stationary contact I02 is integrally formed with the contact carrying member 99 and extends through the stationary contact apertures I6 provided in insulating plates I0, I9, 22, and 31.

In the closed circuit position of the interrupter, not shown, the electrical circuit therethrough comprises (see Fig. 33) line terminals 6, annular terminal and support plate 4, flexible conductor I03, flexible conductor I04 (see Fig, 2), bolt I05, stationary contact I02, movable contact 94, metallic coupling member 95, flexible conductor I06, bolt I95, to the contact carrying member 99 of the lower are extinguishing unit 2 shown in Fig. l. The circuit then extends through the lower arc extinguishing unit 2 of Fig. 1 in the same manner as it extended through the upper arc extinguishing unit 2 of Fig. l. The metallic coupling member I01 of the lower arc extinguishing unit 2 (see Fig. 33) supports two disconnect fingers I08 which are engaged by a conducting actuating member, not shown. The conducting actuating member may be electrically connected to the other terminal of the interrupter by a sliding connection, not shown.

The opening operation of the interrupter shown in Fig. 1 will now be explained. When it is desired to open the electrical circuit passing through the interrupter, or when overload conditions exist in the electrical circuit controlled by the interrupter, suitable operating means, not shown, but which may be of the form shown in Patent 2,138,382 are actuated to permit downward movement of the metallic coupling member it? of the lower arc extinguishing unit 2 of Fig. 1 (see Fig. 33). The metallic coupling member I01 and the two piston members 89 of both units 2 in Fig. 1 move downwardly as a unit, suitable spring means being provided within the housing 5 of Fig. 33, not shown, to bias the insulating operating rod downwardly. As the insulating operating rod 85 and the two insulating support plates 92 of both units 2 move downwardly together as a unit, the movable contacts 94 separate from the stationary contacts I02 to draw an arc, the upper end of which is readily transferred to the upper arcing horn 44.

It will be observed that the downward motion of the insulating first piston member 89 will produce through piston action an upward flow of fluid, in this instance oil, upward in the enlarged portion 49 of the arcing passage 48 to vent through the grating 44a of the upper arcing horn 44 and out of the unit 2 through the rectangular vent apertures I3 provided in insulating plates !0, I9, 22, and 31. This upward flow of fluid is indicated by the arrows in Fig. 1. The volume of the first piston member 89 entering the enlarged portion 49 of the arcing passage 48 is greater than the volume of the metallic coupling member 95 which is leaving the enlarged portion 49 of the arcing passage 48. Consequently, a displacement of fluid within the enlarged. portion 49 results, and this fluid is displaced upwardly in the direction shown by the arrows in Fig. 1 through the arcing horn 44 and out of the unit 2 as previously described. This venting of the fluid upward. and through the rectangular vent passages I3 helps to transfer the upper terminal of the arc to the upper arcing horn 44,

The electrical circuit now through the interrupter comprises line terminal 6 (see Fig. 33),

support plate 4, connector I03, coil connector stud 3.0, connector 32, coil 21, connector 28, coil 26, connector 34, arcing horn screw 36, upper arcing horn 44, the arc itself (not designated), movable contact 94, metallic coupling member 95, flexible conductor I06, bolt [05, flexible conductor I!!! (see Fig. 1), lower coil connector stud 30 through the upper series coils 21, 2B of the lower arc extinguishing unit 2 through the arc, not shown in the lower arc extinguishing unit 2, movable contact 94 of the lower unit 2, metallic coupling member It! (see Fig. 33), disconnect lingers I03, conducting actuating member, not shown, to the other terminal of the interrupterv It will, therefore, be apparent that the transfer of the upper terminal of the arc to the upper arcing horn 44 cuts into series circuit the two series coils 26, 2l' of each arc extinguishing unit 2. These coils produce a magnetic field perpendicu lar to the plane of the drawing of Fig. 1. Assumm ing that the instantaneous current through the interrupter is in a downward direction, the mag-- netic field thus provided is in a direction coming outwards toward the reader perpendicular to the plane of Fig, 1. This magnetic iield acts to bias the arc in a leftward direction, as viewed in Fig. 1, and tends to force the are from the widened portion 49 of the arcing passage 48 through the restricted portion 50 and into the less restricted portion 5|., as more clearly shown in Fig. 3.

During relatively large instantaneous values of arcing current the cross-section of the arc is too large to permit it to enter the restricted portion 50. It is only when the instantaneous value of arcing current is relatively small that the crosssectional area of the arc stream is sufficiently small for it to enter the restricted portion 50 of the arcing passage 48.

It is apparent that during the time that the arc is in the enlarged portion 49 the upward fluid flow, created by the piston action of the piston member or first fluid moving means 89, will serve to wash gas and contaminated fluid out of the units 2 through the upper arcing horns 44 and through the rectangular vent apertures l3. Consequently the dielectric strength within the arcextinguishing units 2 is maintained at a, high value while the arc is positioned in the widened portion 49 of the arcing passage 48. Also, the provision of the venting means, generally designated by the reference numeral H4, in Fig. .l, prevents the internal pressure within the units 2 from attaining too great a value.

As mentioned previously, during relatively low instantaneous values of arcing current, the crosssectional area of the arc is sufliciently small to permit the somewhat diagonal fluid flow caused by the piston action of the first fluid moving means or first piston 69, and coupled with the biasing action exerted by the magnetic field within the units 2, to force the are to the left, as viewed in Fig. 1, through the restricted portion 50 of the arcing passage 48, and into the less restricted portion 5|.

When the arc is in the less restricted portion 5| it is rapidly forced to the left by the fluid flow in the portion 5| provided in the insulating inlet plates 41, which portion communicates with the circular vent aperture l2. The rapid movement to the left of the are into the less restricted portion 5| transfers the lower terminal of the are from the movable contact 94 over to the lower arcing horn 51.

The electrical circuit now through the interrupter is as follows: line terminal 6, support plate 4 (see Fig. 33), connector Hi3, coil connector stud 3B, connector 32, coil 22', connector 28, coil 25, connector 34, arcing horn screw 35, upper arcing horn 44, are ill], lower arcing horn 51, lower arc horn screw 6|, connector 89, coil 65, connector 51, coil 66, connector 12, stud l4, flexible connector ill, flexible conductor I63, coil connector stud 30 of the lower arc extinguishing unit 2 of Fig. 1, through the lower arc extinguishing unit 2 in a similar manner as through the upper unit 2 to the flexible conductor l i2 (see Fig. 33) disconncct fingers Hi8, conducting actuating member, not shown, to the other line terminal of the interrupter.

It will be observed that while the are H0 is positioned within the less restricted portion 5| of the arcing passage 48, it is subjected to a blast of fluid, in this instance oil, through the inlet passages 52 provided in the insulating inlet plates 41 caused by the piston action of the insulating second pistons 8i. it will be observed that the piston chambers 8 are considerably larger in diameter than the insulating pistons 3 l and, consequently, fluid pressure is maintained through all of the inlet passages 52 at the same time.

This feature is very important in the functioning of the insulating pistons 8| that is, the maintaining of the fluid in all of the inlet passages 52 under pressure. Ihe fluid passing through the inlet passages 52 into the less restricted portion 51 of arcing passage 48 and toward the venting passage, generally designated by the reference numeral H3 in Figs. 1 and 3, causes a blast of fluid to contact the are I I0 and to quickly deionize the same at the first current zero and prevents its reignition when the recovery voltage builds up. It will also be observed that the are ill], while in the less restricted portion 51 has ample opportunity to contact fluid disposed in the pockets d5 provided in the insulating plates 42 and 53. Thus, it is apparent that a. large quantity of fluid disposed within the pockets 45 is available to send a blast of un-ionized gas and oil particles into the are core Iii] to deionize the same. The barrier portions 46 disposed in insulating plates 42 and 53 prevent the are Hi] from being swept completely into the venting passage H3.

The direction of the fluid flow is indicated by the arrows in Figs. 1, 3, and 4,

After the arc HE] has been extinguished and the movable contacts 94 are at their full open circuit position, as shown in 1, the conducting actuating member, not shown (see Fig. 33), separates from the disconnect fingers I53 to introduce an isolating gap into the circuit.

During the closing operation, the conducting actuating member, not shown, moves upwardly to engage the disconnect fingers Hill and to move the metallic coupling member ID! and the two piston members 89 disposed in the two units 2 upwardly as a unit against the biasing action of the springs, not shown, disposed in the upper housing 5 (see Fi 33). This upward movement continues until the movable contacts 94 engage the stationary contacts Hit, the compression springs l0! furnishing the requisite contact pres sure between the movable contacts 94 and the stationary contacts I02.

It will be readily apparent from the foregoing description that I have provided piston means for blasting fluid at the arc H0 after it has been moved laterally by the magnetic field through the restricted portion 50 of the arcing passage 48. It is also apparent that the fluid flow through the inlet passages 52 does not strike the are I 10 until the current through the arc III] has a relatively low instantaneous value. Consequently, the piston is not operative to blast the arc during relatively high instantaneous values of arcing current when the are I I i! is positioned in the widened portion 49 of the arcing passage 43, but only strikes the arc I I3 after the latter has passed through the restricted portion 59, and at a time when the instantaneous current is small and when conditions are right for arc extinction.

The flux lines I59 in Fig. 4 indicate schemati cally the direction of the magnetic field in the arc extinguishing units 2 when the current through the arc III) is in a downward direction.

In the embodiment of my invention shown in Figs. 29 through 33, inclusive, the reference numeral II I designates a stationary contact, the lower end of which is disposed through a top metallic plate I and into a modified type of arc extinguishing unit, generally designated by the reference numeral H9. The are extinguishing assemblage, generally designated by the reference numeral IE3, is analogous to the arc extinguishing assemblage I of Fig. 1.

Extending through the top metallic plate I29 are two brackets I2I composed of magnetic material, in this instance iron. At the lower end of each bracket I2I and disposed within the unit H9 is a pole piece I22, more clearly shown in Fig. 32. Disposed between the pole pieces I22 is an upper arcing horn I23 having a grating portion I23a, as more clearly shown in Fig. 30. Screws I24 secure the upper arcing horn I23 to the top metallic plate I23.

A laminated core I25 is secured to the upper ends of the brackets IZI, as shown in Fig. 32. Around the laminated core I25 is wound a series ngagnetizing coil I26, more clearly shown in Fig. 3

A plate member I28 (see Fig. has two 01T- standing integral lever arms I 29 which are pivotally mounted at I33 to the core I25, as more clearly shown in Figs. 30 and 32.

An insulating bracket I3I secured at its lefthand end, as viewed in Fig. 29, to the tie rods I, has a stud I32 slidable therethrough. The lower end of the stud I32 passes through a lug I34, the plate member I28 and is threadedly'secured to the stationary contact I H. A compression spring I33 encircles the stud I32 and is disposed between the insulating bracket I3! and the lug I34 as shown in Fig. 29. It will. therefore, be apparent that the compression spring I33 biases the stationary contact II! in a downward direction, as viewed in Fig. 29. The flexible conductor I21 terminates at its right-hand end in the lug I34.

At the lower end of the arc extinguishing unit II9 are disposed two brackets I35 composed of magnetic material, in this instance iron. At the upper ends of the brackets I35 and extending toward each other are pole pieces I35, preferably integrally formed with the brackets I35. Between the pole pieces I36 is disposed a lower arcing horn I 31, as more clearly shown in Fig. 32. A screw I38 secures the lower arcing horn I31. to the bottom insulating plate I48. A bolt I39 secures the lower arcing horn I3! to the bottom insulating plate I 40 and also serves to bring an electrical connection from the lower arcing horn I31 out of the arc extinguishing unit II 9. Disposed between the brackets I35 is a laminated core I M, more clearly shown in Fig. 32. Around the laminated core I II is wound a magnetizing coil I42.

Within the arc extinguishing unit II 9, and preferably intermediate the ends thereof, is an intensifying magnet structure, generally designated by the reference numeral I43. The intensifying magnet structure I43 comprises a laminated core I44 around which is wound a magnetizing coil I45. Arcing horns I46, I47 are provided and are electrically connected to the magnetizing coil I45 through the terminals I43, I49, as shown more clearly in Fig. 29.

The right-hand ends of the arcing horns I46, I41, as viewed in Fig. 29, are forked, as at I 59 (see Fig. 31) so that the vertical flow of fluid within the enlarged portion 49 of the arcing pas" sage 43 will not be impeded. The vertical direction of flow is indicated by the arrows in Fig. 29. Adjacent the arcing horn I46 are upper pole pieces I5I which are a part of the magnetic circuit through the laminated core I44. Also adjacent the lower arcing horn I41 are lower pole pieces I52 which also are a part of the magnetic circuit passing through the laminated core I44, as shown more clearly in Fig. 32.

In the closed circuit position of the interrupter, the electrical circuit therethrough comprises line terminal 6, conducting support plate 4, conductor I 93, series magnetizing coil I 25, flexible conductor I21, lug I34, stationary contact 1, movable contact 94, metallic coupling member 95, flexible conductor I53, terminal gonductor I54 of magnetizing coil I26 of lower arc extinguishing unit H9, flexible conductor I21, lug I34, stationary contact I I1 of lower arc extinguishing unit I I 9, movable contact 94 of lower unit H9 (not shown) to metallic coupling member I 91 (see Fig. 33), disconnect fingers I08, conducting actuating member, not shown, to the other line terminal of the interrupter.

The opening operation of the interrupter which is shown in Figs. 29 to 33, inclusive, will now be described. When it is desired to open the electrica'l circuit through the interrupter or when overload conditions exist in the electrical circuit controlled by the interrupter, suitable operating mechanism, not shown, moves the conducting actuating member, not shown, downwardly to permit the metallic coupling member IU'I. (see Fig. 33) to move downwardly under the biasing action of the compression springs disposed in the housing 3 (not shown). As in the previously described embodiment of my invention, the metallic coupling member I01 and the two piston members 89 in both are extinguishing units H9 move downwardly as a unit, separating the movable contacts 94 from the stationary contacts I". As in the previous modification of my invention, the upper terminal of the arcs consequently drawn are transferred to the upper arcing horns I23 by the upward flow of fluid out through the vent passages II4 (see Fig. 29).

The top metallic plate I23 serves as an electrical connector between the stationary contact I I1 and the upper arcing horn I23. The electrical circuit now through the interrupter is the same as that previously described with the exception that arcs are interposed between the movable contacts 34 and the upper arcing horns I23. As the piston members 89 move downwardly the lower terminal of the arc is transferred to the arcing horn I43 (see Fig. 29). The reference numeral I55 designates the are which is thus transferred to the arcing horns I23, I 46. As the movable contacts 94 move downwardly past the arcing horns I41, a terminal of the arc transfers to the arcing horn I4! to cut the magnetizing coil I45 into series 11 circuit. The cutting of the magnetizing coil I45 into series circuit creates a magnetic "field within the interior of the arc extinguishing unit II'i-l, as designated by the reference numeral I59 in 32.

When the movable contacts 94 approach the end of their travel, the lower terminal of the arc transfers from the movable contacts 334 to the lower arcing horn I31. This transfer is largely caused by the reaction of the magnetic field set up by the magnetizing coil I45 in the arc extinguishing units H9. The reference numeral I55 designates the position of the are after the lower terminal thereof has transferred to the lower arcing horn I3I. This transfer cuts in the mat netizing coil I42 disposed at the lower end of the arc extinguishing units H9.

The electrical circuit now through the interrupter comprises line terminal 6, conducting sup port plate 4, conductor I03, series magnetizing coil I26, flexible conductor I21, lug I34, stationary contact III, top metallic plate I20, upper arcing horn I23, are I55, arcing horn ME, terminal 48, magnetizing coil I45, terminal hi3, arcing horn I41, arc I55, lower arcing horn I37, bolt I33, ter minal I51 of magnetizing coil I42, magnetizing coil I42, flexible conductor I53, terminal I54 of lower magnetizing coil I26 through the lower arc extinguishing unit H9 in an identical manner through the upper unit IIB to flexible conductor II2, disconnect fingers I08, conducting actuating member, not shown, to the other line terminal of the interrupter.

The deionizing action and the operation of the piston members III are identical to that described previously in connection with the interrupter shown in Fig. 1. Therefore, a further description seems unnecessary. It will, however, be observed that by providing the intensifying magnet structure I43 which is cut into series circuit by the are, a means has been provided to intensify the magnetic field within the arc extinguishing units I I9, and hence to more strongly bias the arc to the left, as viewed in Fig. 29, and through the re stricted portion 50 of arcing passage 48. After the arcs have been extinguished, the actuating mernber, not shown, separates from the disconnect fingers I08 to introduce an isolating gap into the circuit.

Although I have utilized oil as an arc extin guishing fluid, it is to be clearly understood that my invention is applicable to the use of other are extinguishing fluids, for instance, gases or even air. In the latter event the several insulating plates making up the arc extinguishing units 2, H9, may be composed of horn fiber which will evolve an arc extinguishing gas upon being contacted by an arc. The term fluid as used herein and in the appended claims comprises liquids, gases, vapors, and sprays,

Instead of using pistons 8| to produce the pressure within the piston chambers 80 to cause the fluid flow through the inlet passages 52, I may use a series pressure generating arc to produce the requisite pressure. It is to be clearly understood that my invention is not to be limited to the use of piston means, but includes any other suitable pressure generating means.

Although I have shown and described specific structures, it is to be clearly understood that the same were merely for purposes of illustration and that changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention.

I claim as my invention:

ing an arc in the wide porti creating a magnetic field to bias. the are into the restricted portion, one or more inlet passages positioned laterally along the walls of the restricted portion leading into the restricted portion oi the elongated arcing passage, and means operative to force fluid through the in it into the restricted portion to strike t. e are after the arc has entered the restricted portion to assist in its extinction.

2. In a circuit interrupter, an elongated arcing passage having a relatively wide portion and a relatively restricted portion, means for establishing an arc in the wide portion, coil means for creating a magnetic field to bias the are into the restricted portion to effect its extinction therein, the restricted portion being so narrow that the arc enters the restricted portion only during relatively low instantaneous values of arcing current. one or more inlet passages positioned laterally along the walls of the restricted portion leading into the restricted portion oithe elongated arcing passage, and means operative to force fluid through the inlet passages into the restricted portion to strike the are after the arc has entered the restricted portion to assist in its extinction.

3. In circuit interrupter, means for establishing an arc, means for moving the arc laterally only during relatively low instantaneous values of arcing current, and piston means for directing a plurality of jets of fluid at the are on opposite sides thereof at a plurality of spaced points along the length of the are after it has been moved laterally to effect its extinction.

a. In a circuit interrupter, an elongated arcing passage having a relatively wide portion and a relatively restricted portion, means for establishing an arc in the wide portion, means for moving the arc laterally into the restricted portion, at least one fluid inlet passage positioned laterally on one wall of the restricted portion leading into the restricted portion of the elongated arcing pa--- sage, and means for forcing fluid through the inlet passage into the restricted portion to blast the are after it has moved laterally into the stricted portion.

5. In a circuit interrupter, an elongated arcing passage having a relatively wide portion and a relatively restricted portion, means for establish-- ing an. arc in the wide portion, means for moving the arc laterally into the restricted portion, a plurality of fluid inlet passages positioned later ally on one wall of the restricted portion leading into the restricted portion of the elongated arcing passage, and means for forcing fluid through the inlet passages into the restricted portion to blast the arc after it has moved laterally into the restricted portion, the arc only moving laterally into the restricted portion during relatively low instantaneous values of arcing current.

6. In a circuit interrupter, an elongated arcing passage having a relatively wide portion and a relatively restricted portion, means for establish ing an arc in the wide portion, means or moving the arc laterally into the restricted portion. 2:. least one fluid inlet passage positioned laterally on one wall of the restricted portion leading into the restricted portion of the elongated arcing passage, and piston means for forcing fluid through the inlet passage into the restricted portion to blast the are after it has moved laterally into the restricted portion.

7. In acircuit interrupter, means for establishing an arc, means defining a restricted slot into which the arc is moved only during low instantaneous values of arcing current, a piston chamber disposed in a lateral wall of the slot, a plurality of fluid inlet passages leading from the piston chamber laterally into the slot, a piston movable into the piston chamber, the piston having such a small volume as compared with the piston chamber that pressure is maintained through all the inlet passages for forcing fluid therethrough to facilitate the extinction of the arc after the arc has moved into the restricted slot.

8. In a circuit interrupter, means for establishing an arc, means for causing a first flow of fluid substantially longitudinally of the arc, means other than the arc for producing a second flow of fluid, and means comprising the first flow of fluid for moving the arc laterally, the arc contacting the second flow of fluid after having moved laterally to facilitate its extinction.

9. In a circuit interrupter, an elongated arcing passage having a relatively wide portion and a relatively restricted portion, means for establishing an arc in the relatively wide portion, means for moving the arc laterally into the relatively restricted portion only during relatively low instantaneous values of arcing current, and means for directing a plurality of jets of fluid at the are on opposite sides thereof at a plurality of spaced points along the length of the are after it has been moved laterally into the relatively restricted portion to effect its extinction.

10. In a circuit interrupter, an elongated arcing passage having a relatively wide portion and a relatively restricted portion, means for establishing an arc in the relatively wide portion, means for moving'the are laterally into the relatively restricted portion only during relatively low instantaneous values of arcing current, and piston means for directing a plurality of jets of fluid at the are on opposite sides thereof at a plurality of spaced points along the length of the are after it has been moved laterally into the relatively restricted portion to effect its extinction.

11. In a circuit interrupter, means for establishing an arc, means for moving the arc laterally only during relatively low instantaneous values of arcing current, means at least partly of insulating material for forming a plurality of spaced independent fluid inlet passages terminating collectively at a place where the arc will be after it has moved laterally, and means for forcing fluid through the fluid inlet passages so as to strike the are substantially along one side thereof at a plurality of spaced points after it has moved laterally to facilitate its extinction.

12. In a circuit interrupter, means for establishing an arc, means for moving the are laterally only during relatively low instantaneous values of arcing current, means at least partly of insulating material for forming a plurality of spaced independent fluid inlet passages terminating collectively at a place where the arc will be after it has moved laterally, and piston means for forcing fluid through the fluid inlet passages so as to strike the are substantially along one side thereof at a plurality of spaced points after it has moved laterally to facilitate its extinction.

13. In a circuit interrupter, means for establishing an are, means for moving the arc laterally only during relatively low instantaneous values of arcing current, means at least partly of insulating material for forming a plurality of spaced 14 independent fluid inlet passages terminating collectively into two groups on opposite sides of the are at a place where the arc will be after it has moved laterally, and means for forcing fluid through the fluid inlet passages so as to strike the are substantially on opposite sides thereof at a plurality of spaced points along its length after it has moved laterally to effect its extinction.

14. In a circuit interrupter, means for establishing an arc, means for moving the arc laterally only during relatively low instantaneous values of arcing current, means at least partly of in sulating material for forming a plurality of spaced independent fluid inlet passages terminating collectively into two groups on opposite sides of the are at a. place where the arc will be after it has.

moved laterally, and piston means for forcing fluid through the fluid inlet passages so as to strike the are substantially on opposite sides thereof at a plurality of spaced points along its length after it has moved laterally to effect its extinction.

15. In a circuit interrupter, means for establishing an arc, a first fluid moving means to bias the arc laterally, means restraining the lateral movement of the arc until only low instantaneous values of arcing current, and a second independent fluid moving means to force fluid at the are after it has moved laterally to eiIect its extinction.

16. In a circuit interrupter, means for establishing an arc, a first fluid moving means to bias the arc laterally, means restraining the lateral movement of the arc until only low instantaneous values of arcing current, and a second independent fluid moving means to force fluid at the are at a plurality of spaced points along the length of the are after it has moved laterally to effect its extinction.

17. In a circuit interrupter, means for establishing an arc, a first piston means to bias the arc laterally, means restraining the lateral movement of the arc until only low instantaneous values of arcing current, and a second independent piston means to force fluid at the are after it has moved laterally to effect its extinction.

18. In a circuit interrupten'means for establishing an arc, a first piston means to bias the arc laterally, means restraining the lateral movement of the arc until only low instantaneous values of arcing current, and a second independent piston means to force fluid at the are at a plurality of spaced points along the length of the are after it has moved laterally to effect its extinction. 19. In a circuit interrupter, an arc extinguishing unit, means at least partly of insulating materialdefining an elongated arcing passage having a relatively wide portion and a relatively restricted portion, means for establishing an arc in the relatively wide portion, means for moving the are into the relatively restricted portion, two piston chambers spaced on opposite sides of the restricted portion, two piston members simultaneously movable Within the two piston chambers, and at least one fluid inlet passage leading from each piston chamber into the restricted portion to blast fluid laterally at the are after it has entered the restricted portion.

20. In a circuit interrupter, an arc extinguishing unit, means at least partly of insulating material defining an elongated arcing passage having a relatively wide portion and a relatively restricted portion, means for establishing an arc in the relatively wide portion, means for moving the arc into the relatively restricted portion, two

piston Chambers spaced on opposite sides of the restricted portion, two piston members simultaneously movable within the two piston chambers, at least one fluid inlet passage leading from each piston chamber into the restricted portion to blast fluid laterally at the are after it has entered the restricted portion, and the spacing of the restricted portion being so narrow that the arc can only move therein during relatively low instantaneous values of arcing current.

21. In a circuit interrupter, an arc extinguish-' ing unit, means at least partly of insulating material defining an elongated arcing passage having a relatively wide portion and a relatively restricted portion, a relatively stationary contact, a first piston member carrying a movable contact and cooperable with the stationary Contact to establish an arc in the relatively wide portion, the first piston member moving fluid to bias the are into the relatively restricted portion, two piston chambers spaced on opposite sides of the restricted portion, two second piston members simultaneously movable within the two piston chambers, and at least one fluid inlet passage leading from each piston chamber into the restricted portion to blast fluid laterally at the are after it has entered the restricted portion.

22. In a circuit interrupter, an arc extinguishing unit, means at least partly of insulating material defining an elongated arcing passage having a relatively wide portion and a relatively restricted portion, a relatively stationary contact, a first piston member carrying a movable contact and cooperable with the stationary contact to establish an arc in the relatively wide portion, the first piston member moving fluid to bias the are into the relatively restricted portion, two piston chambers spaced on opposite sides of the restricted portion, two second piston members simultaneously movable within the two piston chambers, at least one fluid inlet passage leading from each piston chamber into the restricted portion to blast fluid laterally at the arc after it has entered the restricted portion, and the spacing of the restricted portion being so narrow that the arc can only move therein during relatively low instantaneous values of arcing current 23. In a circuit interrupter, means defining an elongated arcing passage having a relatively wide portion and a relatively restricted portion leading to a less restricted portion, means for establishing an arc in the wide portion, means for moving the arc laterally through the relatively restricted portion and into the less restricted portion, at least one fluid inlet passage positioned laterally on one wall of the less restricted portion leading into the less restricted portion of the elongated arcing passage, and means for forcing fluid through the inlet passage into the less restricted portion to blast the are after it has moved laterally through the restricted portion.

24. In a circuit interrupter, means defining an elongated arcing passage having a relatively wide portion and a relatively restricted portion leading to a less restricted portion, means for establishing an arc in the wide portion, a first fluid moving means for biasing the arc laterally through the relatively restricted portion and into the less restricted portion, at least one fluid inlet passage positioned laterally on one wall of the less restricted portion leading into the less restricted portion of the elongated arcing passage, and second fluid moving means for forcing fluid through the inlet passage into the less restricted portion to blast the are after it has moved laterally through the restricted portion.

25. In a circuit interrupter, an arc extinguishing unit, means defining an elongated arcing passage, the arcing passage including a relatively wide portion and a relatively restricted portion leading to a less restricted portion, means defining venting means beyond the less restricted portion, a relatively stationary contact, a first piston member carrying a movable contact and cooperable with the relatively stationary contact to establish an are within the relatively wide portion of the arcing passage, two piston chambers spaced on opposite sides of the less restricted portion, two second piston members movable within the piston chambers, a plurality of spaced fluid inlet passages leading from each piston chamber to the less restricted portion of the arcing passage, the second piston members being operable to blast fluid at the are on opposite sides thereof from a plurality of spaced points along its length after it has passed through the restricted portion.

' 26. In a circuit interrupter, an arc extinguishing unit, means defining an elongated arcing passage, the arcing passage including a relatively wide portion and a relatively restricted portion leading to a less restricted portion, means defining venting means beyond the less restricted portion, a relatively stationary contact, a first piston member carrying a, movable contact and cooperable with the relatively stationary contact to establish an are within the relatively wide portion of the arcing passage, two piston chambers spaced on opposite sides of the less restricted portion, two second piston members movable within the piston chambers, a plurality of spaced fluid inlet passages leading from each piston chamber to the less restricted portion of the arcing passage, the second piston members being operable to blast fluid at the are 'on opposite sides thereof from a plurality of spaced points along its length after it has passed through the restricted portion and the spacing of the restricted portion being such that the are may only enter through the restricted portion during relatively low instantaneous values of arcing current.

WINTHROP M. LEEDS. 

